Battery Contact Surface Texture for Fretting Corrosion

Solution Overview

Problem

Battery packs experience vibration during operation, leading to fretting corrosion between contacts, which increases electrical resistance and generates heat due to accumulating oxides.

Innovation Solution

The battery pack incorporates a surface texture on its contacts with raised portions and recessed regions to reduce heat generation by allowing oxides to settle away from the contact surface, thereby minimizing additional resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If battery contacts have a smooth surface, then manufacturing is simple, but fretting corrosion causes oxides to accumulate on the contact surface, increasing electrical resistance and generating heat

Engineering Contradiction:

Improvecontact reliabilityVSAvoidcontact surface manufacturing

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The contact surface is given a non-uniform texture with varying depths - deeper regions for oxide accumulation and shallower regions for electrical contact. This local variation in surface quality allows the same surface to serve dual functions: maintaining electrical conductivity while providing oxide storage spaces.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of trying to prevent oxide formation entirely, the invention converts the harmful oxide accumulation into a beneficial feature by providing dedicated recessed regions for oxide storage. The oxides are redirected from the contact surface to specific storage zones, transforming a harmful effect into a controlled, beneficial separation mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Temperature

If battery contacts are designed with surface texture including recessed regions, then oxide accumulation is reduced and heat generation is minimized, but device complexity increases

Engineering Contradiction:

Improvecontact temperatureVSAvoidcontact structure complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The contact surface is given a non-uniform texture with varying depths - deeper regions for oxide accumulation and shallower regions for electrical contact. This local variation in surface quality allows the same surface to serve dual functions: maintaining electrical conductivity while providing oxide storage spaces.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The contact surface incorporates a porous or textured structure with recessed regions that can accommodate oxide accumulation. This porous-like structure provides pathways and spaces for oxides to settle away from the primary contact interface, reducing their harmful effects on electrical conductivity.

Inventive Principle:

Principle #31Porous materials

3Reliability

If battery contacts have raised portions for current transfer, then electrical conductivity is maintained, but the contact surface area is reduced

Engineering Contradiction:

Improveelectrical conductivityVSAvoidcontact surface area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The contact surface is given a non-uniform texture with varying depths - deeper regions for oxide accumulation and shallower regions for electrical contact. This local variation in surface quality allows the same surface to serve dual functions: maintaining electrical conductivity while providing oxide storage spaces.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention transitions from a two-dimensional flat contact surface to a three-dimensional textured surface with raised portions and recessed regions. This dimensional change allows the contact to maintain adequate surface area for conductivity while creating vertical separation between the contact interface and oxide accumulation zones.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The surface texture effectively reduces heat generated by electric current passing through fretting corrosion, improving contact efficiency and extending the lifespan of battery packs by minimizing oxide accumulation.

Implementation Method 1

The rapid movement of the battery contacts relative to the corresponding device contacts may lead to fretting corrosion, which can produce oxides that accumulate on a contact surface

Methodology Applied

Scientific EffectFretting corrosion: Tribocorrosion

Data Source

PatentUS10511008B2Battery contact with a surface texture

Publication Date: 2019.12.17 TTI MACAO COMML OFFSHORE LTD

AI summary

Battery contact with surface texturing. Exemplary battery contacts are located within a battery pack. The battery pack is operable to provide power to a device through a device contact of the device. The battery pack includes a battery pack housing, at least one battery cell located within the battery pack housing, and battery contacts including a positive terminal and a negative terminal. The battery contacts are configured to engage the device contact of the device and allow electric current to transfer from the battery pack to the device. The battery contacts define a surface having a surface texture. The surface texture includes raised portions for contacting the device contact to allow electric current to transfer from the battery pack to the device. The surface texture also includes recessed regions spaced away from the surface and for providing a space between the battery contacts and the device contact.